Electrolytic method, apparatus, and product



M. M. MERRITT.

ELECTROLYTIC METHOD, APPARATUS, AND PRODUCT. APPLICATION FILED 0on7. 1919.

Patented Dec. 21, 1920.

3 SHEETSSHEET I.

luvs-2130:.-

M. M. MERRITT.

ELECTROLYTIC METHOD, APPARATUS, AND PRODUCT.

APPLICATION FILED OCT. I.- 1919.

1,363,186 Patented Dec. 21,1920;

3 SHEETS-SHEET 2.

In?) enior MaZi/fi/ewMMerriii M. M. MERRITT.

ELECTROLYTIC METHOD, APPARATUS, AND PRODUCT- APPLICATION FILED ocr. 7, 1919.

1,363,186, Patented Dec; 21,1920.

3 SHEETS-SHE ET 3- 1 21226111703".- 'miihewMMernifi,

UNITED STATES PATENT OFFICE.

MATTHEW M. MERRITT, OF SOUTH MIDDLETON, MASSACHUSETTS.

ELECTROLYTIC METHOD, APPARATUS, AND PRODUCT.

Speeification of Letters Patent. Patented Deb, 21, 1920.

Original application filed April 15, 1919, Serial No. 290.152. Divided and this application filed october To (17/ 7F]! 0m it may cancer-n.

Be it known that I, MATTHEW M. MER-' electrolyte flows in a stream past the cathode or cathodes, the anodespreferably being distributed in the stream longitudinally thereof and preferably in comparatively close relationship to the cathode surface or surfaces. a

Another aspect of-the invention relates to the. circulation of the eletrolyte in such away that an opportunity'is afforded-for the same to rest so that hydrogen may have an opportunity to escapefrom the body of the electrolyte during a period when the electrolyte is-no't being used actively as an electrolytic agent.

Another aspect of the invention includes the'aeration thereof in any suitable way," but preferably by permitting the electrolyte .to fall through theaira sufficient distance to accomplish this .purpose. I I

While the most important features of my invention are of general application in the electrolytic art; and are useful in making all electrolytically?deposited or coated articles or products, I have elected, without 'limitation thereto',-;to disclose the same in con:

nection. with. the depositpf metal on elongated cathodes in connection with the manufacture ofelectrolytically coated wire and similar products such astubes formed by electrolytically depositing. metal on elongated cathodes adapted to be removed after electro-deposition, leaving the electrolytically deposited shell to form the tube or pipe. Vhere my invention is applied to the manufacture of coated wire, tubing or pipe, it preferably includes the passage of the wire or other cathode through the electrolytic bath so that each portion of an elongated flexible cathode may be, if desired, subbodiment of a preferred form of vFig. 2; v I

Fig. 4 is a section'on the line of Serial No. 328,999.

jected to electrolytic action under substantially constant conditions and for substantially the same length of time.

While many features of my invention are of general application, and may be used for any purpose in connection with the deposi-' tion of any metal on any form of cathode, I l

have elected in this application specifically to describe the same in connection with the electro-deposition of copper on a steel cath-.

ode, of copper on an aluminum cathode (preferably treated as hereinafter more fully described), and in connection with the electro-deposition of cop or on a fusible or otherwise removable cat ode, the latter bemg primarily useful in connection with the formation of tubing. 1

This application is a division of my copending application, Serial No. 290,152, filed April 15, 1919. I Thedrawings-show an illustrative emapparatus useful in connection with practising my improved process as applied to the manufacture of wlre, tubing and the like. i Figure 1 isa longitudinal section, partly in elevation, illustrating diagrammatically certain preferred forms of apparatus used quent to suitable treatment, hereinafter described, of the a paratus shown in Fig. 1; I

Fig. 3 is a plan of the apparatus shown in Fig. 2; Fig. 2; and

Fig. 6 is a section through a preferred form of apparatus for removing the fusible 5 is'a'section on the line 5-5 of Fig.

cathode material from tubing made by my.

method and apparatus.

I will first describe rather specifically, though without limitation of the broader aspects of my invention, the operation of the apparatus shown in the drawings in connection with the manufacture of copper coated node material by the ap steel wire. Steel, iron or other suitable wire 7, preferably coiled on a drum 8, may be drawn from the drum 8 and initially passed through a cleansing agent, preferably muriatic acid and tin chlorid in the tank 9, the wire thence passing under a stream. of water 10 to remove any acid which may cling to the surface thereof, and thence into an alkaline bath,-preferably cyanid, in the tank 11. This bath 11 is preferably provided with a suitable anode 12, which may beof copper, a negative connection 13 being made to the wire preferably before entering the bath 11. The wire may befed at any suitable speed, but is preferably immersed in the cyanid bath 11 for a sufiicient length of time to plate the wire with. copper so as to protect the steel from the subsequent action of the acid when deposition is carried on in an acid bath as hereinafter described. The current density used in connection with plating in this cyanid bath may be as is usual in copper plating processes.

After the wire leaves the cyanid bath 11, it is again washed, preferably by passingthrough a glass tube 14 into which a stream of water isintroduced at 15, this providing a very simple and eflicient rinsing medium. The wire, thus plated in the cyanid bath and rinsed, is then passed to the apparatus in which further electro-deposition of metal is rapidly carried on under high current density, 7

Perhaps the most important feature of my improved apparatus and method, which feature is applicableto all kinds of electro-deposition of all metals on all forms of cathodes, includes the passing of the electrolyte in a streampast the cathode. This stream 'may conveniently be confined in a trough, which may, if desired, slant in two directions as best shown in Fig. 2, the

electrolyte being introduced into the trough at 16 and flowing in opposite directions through the trough or troughs 17, 18 and thence flowing into a reservoir or tank 19.

The discharge ends of the troughs arepreferably at a sufficient distanceabove the level of the electrolyte in the tank or reservoir 19 20. To increase the conductivity of the elec-.

trolyte, and to facilitate the escape of hydrogen bubbles, I preferably provide a steam coil or other heating agent for heating the electrolyte in the tank 19.

other portions of the apparatus and other 1 steps of the method, or whether used separately in any connection. For instance, while I have shown the trough sloping in two directions, it is obvious that a trough sloping in one direction, or any means or suitable mechanism for producing a flow of the electrolyte, is of use. It is also clear that, while I have shown the flow of elec? trolyte in connection with the electro-deposition on wire, that the flow of the electrolyte is useful when used in connection with cathodes of any kind, whether individual articles continuously immersed in the flow, or whether individual articles intermittently immersed in the flow. It should also be understood that the preferable aeration of the electrolyte, while preferably provided by the fall of the electrolyte from theend or ends of the trough or troughs, may be effected in other ways, and that the provision of means for permitting the electrolyte to rest, preferably while heated, may be of use in connection with electrolytic proc-' esses differing greatly in other details from those herein described. Similarly, while the various features of my apparatus'and steps of my method are peculiarly useful in their cooperative relationship, it should be understood that each may be of use in other connections.

Returning to the specific embodiment of my invention shown in the drawings, the

wire 7 preferably passes through the trough or troughs 17, 18 a plurality of times, being passed preferably in a generally helicoidal relationship about a series of preferably independently rotatable sheaves arranged in tiers 21', 22 at opposite ends .of the troughs, thus providing a continuous length of wire making up two runs, each run prefer ably including several passages of the wire.

The runs correspond {to the opposite sides of a helicoid viewed as a whole, and

the several passages of the wire making up each run correspond to the ndividual turns making up the sides ofthe helicoid. The tiers of sheaves 21 and 22 may be conveniently used as negative contacts for conducting the current rendering the wires carried by the sheaves. the cathodes of the apparatus. p

In order to provide for close proximity of the anode material to the wire, I preferably duplicate the troughs 17, 18, providing corresponding trough or troughs for each of the wire. Thus, as best viewed in 1,sas,1ee

Fig. 3, the run 23 cooperates with the double inclined troughs 17, 18, and therun 24 of the wire cooperates and passes through the troughs 17', 18 fed by acouduit 16 corresponding tothe conduit 16 from the pump 20. Thetroughs 17,18and 17 18are preferably, 'as'shown, relatively narrow, or, n any case, preferably provide anode surfaces relatively closeto the cath-.v odes. As best viewed in Fig. 5,"the anodes may be composed of copper sheets or copper scrap retained behind suitable screens such as theperforated lead sheets 40. Anyxsuitable positive connection may be made with increased or decreased to'correspond to, increase or decrease 1n the number of passages of the wire making up' each run.

The troughs maybe of any suitable length, but I have found by experiment that troughs sloping in one direction thirty feet long, and having a fall of four inches, are satisfactory, and similarly that a trough sloping in two directions, as shown on the drawings, thirty feet long and having a slope of two inches toward each end thereof, provides a very desirable rate of flow, approximating preferably one hundred and thlrty feet per minute. v

I have shown in Fig. 4 a cross-section on the line 4-4 of Fig. 2, Fig. 4 being on an enlarged scale and showing details of the troughs and cooperating parts adjacent the center of the apparatus. Where troughs sloping in two directions are used, I may provide suitable separatin means for the Wires to prevent contact 0 one against the other, herein shown as glass rollers 25. While I preferably make my process a continuous one, joining one roll of wire to the next, it is sometimes necessary to suspend operations and to pass a new wire through the system by a threading, as distinguished from a drawing, operation. To facilitate this, I have provided mechanism, best shown in Figs. 2 and 5, for dropping the tanks away from their operative position so as to permit ready passage of the wire about the sheaves and through the rollers 25. To facilitate raising and lowering of the tanks, I

l 1ave shown racks 26, 26 cooperatingwith pinions 27, 27mounted on shafts 28, 28 and adapted to be turned by cranks 29, 29 and adapted to be locked against undesired rotation by any suitable mechanism, typified by the dog or pawl 30. The troughs 17 and 17 may be guided in their vertical movement in any suitable way,typified by the guides 31, 31 engaging vertical members of a bridge or framework 32'passing above the troughs and supported or guided at their inner sides ,b rollers 33. The glass rollers 25, hereinbe ore described, are preferably suspended in frameworks 34, 34 from the bridge 32, which may conveniently also support the discharge conduits or nozzles As heretofore stated, the current density preferably much higher than the current density utilized in connection with the cyanid bath 11. The rate of deposit on the various portions of the wire exposed to ele'ctrolytic action in the trou hs varies in proportion to the length of time that the various parts of the wire have been exposed to electrolytic action, the wire as it first enters the trough after being washed pursuantto the cyanid bath being only slightly covered by the cyanid plating operation, and being of comparatively small cross-section and of comparatively slight electrical conductivity as compared with the cross-section and electrical conductivity after considerable electrodeposition has taken place in the troughs. Itmay be roughly said that the wire at any given time exposed to electrolytic action in actly the same treatment as each other portion, the wire as it leaves the finishing point is of uniform diameter-and conductivity.

The power for conducting or drawing the wire through the various operations heretofore described may be applied to the winch 35, about which the wire is passed before passing on to a winding drum 36 which is driven through a clutch adapted to slip to compensate for changes in diameter of the drum as the wire is wound thereon. The winch 35 determines the speed at which the wire passes through the apparatus.

Just before the wire goes on to the winch, it is preferably washed by washing apparatus 37.

Where the apparatus is used for the dep osition of copper on a cathode composed of than aluminum which will readily take in.

a satisfactory manner the deposit of copper .or other metal during subsequent electroutilized in connection with the troughs is the troughs takes the form of a truncated deposition. The oxid-excluding medium is preferably tin, and I may effect the combined deoxidizing and tinning operation by supplying the pipe 15 with a mixture, of. muriatic acid, water and tin chlorid; -To obviate the necessity for too rapid circulation of this'liquid, I may provide a sponge on the interior of the tube 14 to absorb and this method is of great utility in this connection, it will be understood that this feature of my invention may be useful in other connections such as the preparation of any object made of aluminum or surfaced with aluminum for electro-deposition. The interposition of the coating of oxid-excluding medium between the aluminum and the copper minimizes that galvanic deterioration of these metalswhich normally arises where, in the presence of even a trace of moisture, copper and aluminum are permitted to come into contact or even into closeproximity.

Where my improved method and apparatus is used in connection with the manufacture of tubing and pipes, a cathode of fusilble metal or any other suitable conductive substance, or even a non-conductive substance coated with a conductive substance, is substituted for the initial coil of steel wire on the drum 8. Where this readily fusible or otherwise removable core or cathode is composed of lead or an alloy of tin and lead or-the like, it is not essential that any preliminary treatment be given prior to starting of electro-deposition in the flowing electrolyte, but where it is desired to provide a tube having an interior coating of tin, I may pass the cathode through an alkaline bath, corresponding to the cyanid bath 11, in which I electrolytically deposit copper on the'surface of the fusible metal cathode prior to the electro-deposition of copper or other metal in an acid bath. The passage of the cathode through the flowing electrolyte may be the same as in the case of coating wire, as hereinbefore described, and after electrodeposition is completed the cathode with the electro-deposited metal thereon may be wound in the form of a helix and placed in a melting furnace, shown in Fig. 6, the entire coil being heated to a point suflicient to melt the readily fusible core, but not sufiicient to melt the copper surface, and air pressure being applied at 38 to blow the melted fused core from the interior of the tube.- Where the initial deposit of copper on the fusible cathode has been made m a n .the fusible core will adhere to the interior surface, thus providing a perfectly smooth and perfectly tinned lining to the tube.

The use of an electrolyte which is flowing during electro deposition enables me to use a much higher current density than has been possible, while securing satisfactory results, in any electro-depositing process heretofore considered possible. I. have secured finegrained, smooth, ductile, uniform, homogeneous electro deposits in connection with this method and apparatus while using a current density up to one thousand ampTeres persquare foot of cathode surface.

one of the deleterious results of the formation of hydrogen bubbles on the cathode, commonly known as spongy deposit, are present where my apparatus and process is utilized. This is due to rapid liberation of the hydrogen arising from several causes; first, the rapid passage of the electrolyte past the cathode surface; second, the fact that no given portion of the electrolyte is actively used continuously for any considerable length of time; third, the fact that no given portion of the electrolyte acts more than momentarily on any given portion of the cathode surface; fourth, the fact that the electrolyte is given an opportunity to rest between theiperiods of recurrent use of any portion thereof, thus providing a time for liberation of the hydrogen and for settlement of any foreign substance heavier than the electrolyte; fifth, the fact that the reservoir 19 provides an opportunity for a lower stratum in which the impurities can settle, an upper stratum in which the hydrogen can be liberated, and an intermediatestratum comparatively clean from which the supply of electrolyte to the trough or troughs can be drawn; sixth, where the apparatus and method is used in connection with the manufacture of aicontinuous article, such as specifically described herein, the preferably constant passage of the article through the electrolyte insures the absolute uniform treatment of all portions of the cathode, and if, for any reason, condimeans for passing a continuous stream of from the scope of my invention,-w

'mits heating of the same for a considerable length of time between intermittent periods of use of any iven portion of the bath.

.The amount of e ectrolyte actually subject to electrolytic action at any one time may be almost netgli ible in-compa'rison with the amount 0 electrolyte in the reservolr.

While I have shown in the drawings and describedl rather specifically a. preferred other changes in the apparatus as a whole or in parts thereof, and even changesof'similar or reater scope in connection with the met od,- maybe made without departlng best defined by the .following claims.

Claims.

'1. Electrolytic apparatus, comprising the electrolyt'epast the cathode.

2. Electrolytldap aratuscomprising, in combination, nieans or passing a continuous stream of the electrolyte past the cathode, and anode surfaces for renewing the ionic supplg'to said stream.

3. lectrolytic apparatus comprising, in combination, means or passing a continuous stream of the electrolyte past the cathode, and anode surfaces for renewing the ionic supply to said stream, said anode surfaces being distributed lengthwise of the stream.

4. An electrolytic apparatus comprising, in combination, means for passing a continuous stream of the electrolyte past the cathode, and anode surfaces for renewing the ionic supply to said stream, said anode surfaces being distributed lengthwise of the stream and in relatively close proximity to the cathode surface or surfaces.

5. Electrolytic apparatus comprising, in combination, a trough, means for introducing a stream of electrolyte into said trough, a reservoir for receiving the electrolyte passing from said trough, and circulatory means for drawing the electrolyte from said reservoir and returning the same to said trough.

'6. Electrolytic apparatus comprising, in combination, a trough, means for introducing a stream of electrolyte into said trough, a reservoir for receiving the electrolyte passing from said trough, and circulatory means for drawing the electrolyte from said reservoir'and returning the same to said trough, said reservoir containing an amount of electrolyte very substantially greater than the amount contained at any one time in said electrolyte through said conduit past the cathode.

rich is 8. Electrolytic apparatus-comprising, in' combination, a'trough' sloping in two directions, reservoirmeans for r'eceiving'the flow of electrolyte from each end of said trough, and means for. introducing a'st'ream'ofel'ed trolyte to said trough at a point ad'a'cent the highest point ofthe bottom. thereo Q i V 9. Electrolytic apparatus 'comprising, in l combinatiom means for rogressively advancing a flexible cathodeto provide'za plu 'rality of runs, each including several pas-f sages of cathodematerialand1-a p1ur'alityfof' conduits, one for each of sai d,runs,.for con finigg a stream of fiowing electrolyte[activat to'efi'eot electro-depositio'n-on the-cath- 30 ode material, j -.f

'10; Electrolytic apparatus! comprising, in combination, cathode supportin means," troughs for confining a stream ofje ectrolyte in proximity to the cathode rmaterial and means for raising and lowering "said troughs into working or non-workingposition relative to the cathode material.

11. Electrolytic apparatus.comp-rising, in combination, circulating means for circulating. the electrolyte in a swift-flowing stream passing the cathode, and means providing an opportunity for rest of the electrolyte between recurrentpassage thereof to said circulating means.

12. Electrolytic apparatus comprising, in combination, a trough, aplurality of passages of flexible cathode material passing through said'trough, a stream of electrolyte discharging into said trough and means for separatlng said passages of flexible cathode material adjacent the point of entrance of said stream of electrolyte.

13. Apparatus foruse in connection with electro-deposition comprising a sloping trough, anode material distributed longitudinally of the trough and means for circulating the electrolyte through the trough.

1 1. Apparatus for use ilrconnection with. electro-deposition comprising a sloping110 trough, anode material distributedlongitudinally of the trough, meansfor circulating the electrolyte through the trough and means for aerating the electrolyte.

15. Apparatus for use in connection with electro deposition comprising a sloping trough, anode material, distributed longitudinally of the trough, means for circulating the electrolyte through the trough and means for aerating the electrolyte by passing the same over a fall.

16. Apparatus" for use in connection with electro deposition comprising a sloping trough, anode material distributed longitudinally of the trough, means for circulating the electrolyte through the trough and cathode retainers at the sides of the trough.

17. Apparatus for coating an elongated flexible element comprising, in combination, initial coating means for initially coating said element with a relatively thin protective film, and other coating means for subsequently electrolytically depositing copper thereon.

l8. Electrolytic apparatus comprising, in combination, a sloping trough and means for supplying a stream of electrolyte thereto at a rate which, in combination with the slope of said trough, provides a flow of the electrolyte at a rate exceeding one hundred feet per minute.

19. Electrolytic apparatus comprising, in combination, a slopin trough means for supplying a stream 0 electrolyte thereto,

said trough being relatively narrow and hav ing anode material distributed lengthwise thereof. 7

20. Electrolytic apparatus comprising, in combination, a sloping trough, means for supplying a stream of electrolyte thereto, said trough being relatively narrow and hav-' ing anode material distributed lengthwise thereof in relatively close proximity to the cathode. I r

In testimony whereof, I have signed my name to this specification.

MATTHEW M. MERRITT. 

